LOCATION RUCH OREstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Mollic Palexeralfs
TYPICAL PEDON: Ruch gravelly silt loam, woodland. (Colors are for moist soil unless otherwise noted.)
0i--3/4 inch to 0; partially decomposed litter of leaves, needles and twigs.
A1--0 to 2 inches; dark brown (7.5YR 3/3) gravelly silt loam, brown (10YR 5/3) dry; moderate very fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; many interstitial pores; 20 percent gravel; slightly acid (pH 6.3); abrupt smooth boundary. (1 to 3 inches thick)
A2--2 to 7 inches; dark brown (7.5YR 4/4) gravelly silt loam, light yellowish brown (10YR 6/4) dry; weak medium subangular blocky structure parting to moderate very fine granular; hard, friable, slightly sticky and slightly plastic; many roots; many very fine tubular and interstitial pores; 20 percent gravel; moderately acid (pH 6.0); clear smooth boundary. (4 to 6 inches thick)
BAt--7 to 17 inches; reddish brown (5YR 4/4) loam, light brown (7.5YR 6/4) dry; weak medium subangular blocky structure parting to moderate fine subangular blocky; hard, firm, sticky and plastic; many roots; many very fine tubular pores; few faint red (2.5YR 4/6) clay films in pores; 10 percent gravel; common 2 to 4 mm black concretions; moderately acid (pH 5.8); clear wavy boundary. (0 to 12 inches thick)
Bt1--17 to 26 inches; yellowish red (5YR 4/6) loam, yellowish red (5YR 5/6) dry; moderate fine subangular blocky structure; very hard, firm, sticky and plastic; common roots; many very fine tubular pores; common distinct red (2.5YR 4/6) clay films on faces of peds; common 2 to 4 mm black concretions; few black stains; 10 percent partially weathered gravel; moderately acid (pH 5.8); gradual wavy boundary. (8 to 12 inches thick)
Bt2--26 to 46 inches; yellowish red (5YR 4/6) loam, yellowish red (5YR 5/6) dry; moderate fine subangular blocky structure; very hard, firm, sticky and plastic; few roots; many very fine tubular pores; common distinct red (2.5YR 4/6) clay films on faces of peds; common 2 to 4 mm black concretions; few black stains; 5 percent partially weathered gravel; moderately acid (pH 6.0); gradual wavy boundary. (10 to 24 inches thick)
Bt3--46 to 70 inches; yellowish red (5YR 4/6) loam, yellowish red (5YR 5/6) dry; moderate medium subangular blocky structure; very hard, firm, sticky and plastic; few roots; many very fine tubular pores; common distinct red (2.5YR 4/6) clay films on faces of peds; common 2 to 4 mm black concretions; 10 percent partially weathered gravel; slightly acid (pH 6.1).
TYPE LOCATION: Jackson County, Oregon; about 2 miles north of Ruch, approximately 520 feet west and 540 feet south of the northeast corner of sec. 15, T. 38 S., R. 3 W., Willamette Meridian.
RANGE IN CHARACTERISTICS: The soils are usually moist but are dry for 80 to 110 consecutive days throughout the moisture control section. The mean annual soil temperature is 52 to 57 degrees F. Depth to bedrock is more than 60 inches. Solum thickness is over 60 inches.
The A horizon has hue of 7.5YR or 10YR, value of 3 through 5 moist, 4 through 6 dry, and chroma of 2 through 4 moist and dry. It is loam, silt loam, or gravelly silt loam with 12 to 20 percent clay. It has 0 to 30 percent gravel. It has 1 to 3 percent organic matter. It is slightly acid or neutral.
The Bt horizon has hue of 5YR or 7.5YR, value of 3 or 4 moist, 5 or 6 dry, and chroma of 4 through 6 moist and dry. It is loam or clay loam and averages 25 to 35 percent clay with 18 to 25 percent sand coarser than very fine sand but finer than coarse sand. It has 5 to 15 percent partially weathered gravel and 0 to 5 percent partially weathered cobbles. Uncoated sand and silt layers are common in the upper part of the B horizon in some pedons. It is moderately or slightly acid.
COMPETING SERIES: There are no competing series in this family.
GEOGRAPHIC SETTING: Ruch soils are on high stream terraces, alluvial fans, and footslopes at elevations of 300 to 3,000 feet. Slopes are 2 to 60 percent. The soils formed in mixed alluvium weathered from altered sedimentary and extrusive igneous rocks. The mean annual precipitation is typicaly 20 to 60 inches but may range to 90 inches in the interior valleys of Curry County, Oregon. The mean January temperature is 35 to 40 degrees F, mean July temperature is 70 to 74 degrees F., and mean annual temperature is 50 to 56 degrees F. The frost-free period is 140 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Caris, Offenbacher, Selmac, Vannoy and Voorhies soils. All of these soils except Selmac are 20 to 40 inches deep to bedrock. Also, Caris and Offenbacher soils lack an argillic horizon. Selmac soils are greater than 60 inches deep to bedrock, have an argillic horizon, and are moderately well drained.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderately slow permeability.
USE AND VEGETATION: Pasture, hay, small grains, homesites and timber production. Natural vegetation consists of an open stand of Douglas fir, ponderosa pine, California black oak, Pacific madrone, shrubs, forbs, and grasses.
DISTRIBUTION AND EXTENT: Interior valleys of southwestern Oregon; MLRA 5. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Josephine County, Oregon, 1979.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon
Argillic horizon - from depths of 7 to 70 inches (BAt, Bt1, Bt2, Bt3, horizons)
Pale feature - soil has an argillic horizon which has both no clay decrease with increasing depth of 20 percent or more (relative) from the maximum clay content; and in the matrix of it's lowest subhorizon has a hue of 7.5YR or redder and chroma of 5 or more.
Particle-size control section - from 7 to 27 inches (BAt, Bt1, and part of the Bt2 horizons).
ADDITIONAL DATA: Characterization data on two profiles (S69 Oreg. 15-2 and S69 Oreg. 15-6) reported on SCS Riverside Soil Survey Laboratory computer printout for the soils sampled for the Rogue River project. S69 Oreg. 15-2 is modal.